DESCRIPTION: (Applicant's Description) Since the discovery of the ozone hole in winter of 1978-1979, it has become increasingly clear that humans through their use of certain halogenated compounds have decreased the ambient ozone levels in the stratosphere. The decrease in ozone associated with human activities results in a significant increase in ultraviolet radiation. Because of UV's biologic effects, it is highly likely that ozone depletion will result in an increase in the incidence or severity of such effects. In humans, two of the most important such effects are skin cancer and cataract. Data by which to assess the carcinogenic risks to humans from ozone depletion, at least in terms of squalmous cell carcinoma (SCC) are relatively robust. However, data with which to assess the cataract risks posed by ozone depletion heretofore have been relatively poor. The work proposed in this application is designed to develop the appropriate dose-response information from the Salisbury Eye Evaluation Project and then use it to develop risk estimates for the US population over the next 100+ years. The steps involve: 1) Convert the exposure data to the needed units 2) couple exposure to the cataract data and determine the dose response 3) relate dose response to increase in U.V. from ozone depletion. Such data are urgently needed to inform the Governmental program on sun safety.